Prohibited Chemical Allowed in Lubes


Prohibited Chemical Allowed in Lubes
A close up of a steel hydraulic arm. Applications for phenol, isopropylated phosphate (3:1) include hydraulic fluids, along with other lubricants and greases. © Istvan /

The United States Environmental Protection Agency last month excluded the lubricant industry from a new prohibition on phenol isopropylated phosphate (3:1) – a chemical that provides anti-wear and anti-compressibility performance in products such as aviation hydraulic fluids.

Phenol isopropylated phosphate (3:1) – also referred to as PIP (3:1) – was one of five chemicals banned as a result of an expedited rulemaking after the agency concluded that they not only toxic to humans and wildlife but that they are also persistent and bioaccumulative, meaning that they do not decay and build up in the bodies of humans and predator species. The agency considers such behavior to be a major hazard.

The agency’s final rules, published Dec. 22, prohibits the chemicals in question from being manufactured, imported, processed or distributed in the U.S. The prohibition on PIP (3:1), however, includes several exceptions, including use of the chemical in lubricants and greases. The agency explained that it allowed the exception after receiving input from the industry that it uses the chemical in applications with severe operating conditions, such as very high temperatures, and that practical replacement chemicals are not available.

The agency added also said that the risks posed by PIP (3:1)’s use in lubes could be mitigated by requirements that employers adopt safe practices and rules prohibiting the chemical’s release into the environment.

“EPA does not expect lubricants and greases containing PIP (3:1) to be available to consumers or workers in non-industrial settings, as lubricants and greases that contain PIP (3:1) are those that need to function in extreme environments, including extreme heat, cold, and high pressure,” the agency wrote.

The rule also provides a specific exception for use of the chemical used in hydraulic fluids used in commercial aviation or in military applications where no alternative chemicals are available. Explaining that exception, the agency cited input from several industry sources advising that hydraulic fluids are critical to safe operation of aircraft and that the process of developing products with replacement chemicals is long and uncertain.

“Several of those comments supported the concerns outlined in the proposed rule, namely that aviation fluids are approved by major aircraft manufacturers who work closely with the Federal Aviation Administration, and any change in formula composition results in a full requalification process,” the agency wrote.

“As described in the proposed rule, this process is a joint effort between the fluid manufacturer and aircraft manufacturer, and resulting fluids are subject to extensive laboratory and field testing. At the end of this iterative evaluation process, there is no guarantee that a technically equivalent alternative will be developed.”

The agency noted that the exception for lubricants and greases includes products such as metalworking fluids. The agency did not include a time limit on the exceptions for the lubricants industry, as it did on some other exceptions.